DE102019203253B3 - Cooling unit for a heat exchanger - Google Patents

Abstract

The invention relates to a cooling unit for a heat exchanger, preferably for a heat exchanger integrated in an oxygenator for tempering blood conducted in an extracorporeal blood circuit, with a storage container holding a liquid, a reaction container comprising a reactant, which in connection with the liquid has an endothermic temperature Is able to initiate a reaction, a functional means generating a fluidic access between the storage container and the reaction container, and a fluid line running at least in regions within the reaction container, which has an inlet and outlet line, each of which can be connected or connected in a fluid-tight manner to a hose line system of the heat exchanger, and forms at least part of a fluid circuit with the hose line system of the heat exchanger. The invention is characterized in that an expansion tank is provided with an overflow into which the flue Liquid flows from the reservoir after the fluidic access has been generated between the reservoir and the reaction container such that the overflow represents a fluid connection to the reaction container through which a portion of the stored liquid reaches the reaction container to initiate the endothermic reaction with the reactant, and that the fluid line is fluid with the expansion container is connected, into which a residual portion of the stored liquid from the storage container arrives, and that a fluid pump is arranged along the fluid line, by means of which liquid reaches the fluid line from the expansion container into the fluid line running at least in regions within the reaction container.

Description

Technical field

The invention relates to a cooling unit for a heat exchanger, preferably for a heat exchanger integrated in an oxygenator for the temperature control of blood conducted in an extracorporeal blood circuit, with a storage container holding a liquid, a reaction container comprising a reactant, which in connection with the liquid has an endothermic temperature Is able to initiate a reaction, a functional means generating a fluidic access between the storage container and the reaction container, and a fluid line running at least in regions within the reaction container, which has an inlet and outlet line, which are each fluid-tightly connectable or connected to a hose line system of the heat exchanger, and forms at least part of a fluid circuit with the hose line system of the heat exchanger.

A device for temperature control based on a chemical reaction and its use as a temperature control unit for a heat exchanger is in the document DE 10 2017 211 671 A1 described. The known device uses a container partially filled with granular urea, in which a second container filled with water with a deformable container wall is introduced. For cooling purposes, the water pours from the second container into the first container and reacts with the urea to form a positive reaction enthalpy, which is technically usable through thermal coupling.

State of the art

It is known to use the heat or cold released in exothermic or endothermic chemical reactions by technical coupling. In the case of endothermic reactions in which cold is released, there are a large number of applications, which are briefly outlined below.

In the context of cardiac surgery or intensive medicine, in particular for the treatment of acute heart and / or lung failure, cardiopulmonary machines are used with which the pumping function of the heart and the pulmonary function can be replaced for a limited period of time. The blood leaves the body via an extracorporeal blood circuit in the form of a tube system, is enriched with oxygen with the help of an oxygenator, which is part of the heart-lung machine, and returned to the body. The oxygenator takes on the function of the lungs and not only supplies the blood with vital oxygen, but at the same time removes the carbon dioxide (CO2) generated by metabolic processes.

All oxygenators used today also have a heat exchanger, with the help of which the blood flowing through can be warmed but in particular cooled. The heart interventions usually take place under hypothermic conditions, i.e. The blood is cooled more or less because the lowering of the body temperature reduces the metabolic activity of the cells and increases the ischemia tolerance of the affected tissues and organs.

So-called hypothermia devices serve as cold sources, in which cooled water is generally generated and used as cooling liquid in order to cool the blood flowing through the oxygenator via a heat exchanger, i.e. to withdraw its thermal energy in a targeted manner. Commercial hypothermia devices are large-scale and heavy-weight control units, usually mounted on rollers, whose heating and cooling units are supplied by mains power and are therefore not suitable for use in the field.

Due to their compact design and largely autonomous power and cooling water supply, modern hypothermic devices enable portable use, regardless of electrical power and water supply. Such hypothermic devices provide fluid-tight connections for a heat exchanger integrated in the oxygenator, so that they can be used in a modular or integrative manner. an oxygenator can be used.

The principle of refrigeration in such largely autonomous, modern hypothermic devices is based on an endothermic chemical reaction, usually between ammonium nitrate, calcium ammonium nitrate or urea and water. Urea is often used as a chemical component in cold packs in order to generate a rapid cooling effect. These usually exist. from two separate areas, one of which is in one urea, in the other water. If the separation is removed, the urea dissolves in the water. Since the lattice energy of urea is greater than the hydration energy, the dissolution process draws energy from the environment and cools it down, see Robert T. Sataloff: Sataloff's Comprehensive Textbook of Otolaryngology. Jaypee Brothers, 2016, ISBN 978-93-5152745-9, p. 412 ..

The publication US 2014/0371552 A1 discloses a blood sugar measuring device which can be placed non-invasively on the skin surface of a patient and which comprises a cooling device, a temperature measuring device and an infrared radiation detector. For the purpose of measuring blood sugar, the Skin surface reduced to a predetermined temperature by means of the cooling device and the infrared radiation emitted or absorbed by the skin surface is measured. The cooling device consists of two fluid-tight and directly adjacent chambers, one of which is filled with urea and the other with water. With the aid of a spring-loaded mandrel, a partition that separates the two chambers in a fluid-tight manner can be perforated locally, so that the water pours into the urea chamber, thereby initiating an endothermic reaction that removes heat energy from the surroundings and cools the skin surface to be measured in a predetermined manner.

Presentation of the invention

The invention is based on the object of a cooling unit for a heat exchanger, preferably for a heat exchanger integrated in an oxygenator for the temperature control of blood conducted in an extracorporeal blood circuit, with a storage container holding a liquid, a reaction container comprising a reaction medium, which in connection with the liquid is able to initiate an endothermic reaction, a functional means generating a fluidic access between the storage container and the reaction container, and a fluid line running at least in regions within the reaction container, which has an inlet and outlet line, each of which can be connected in a fluid-tight manner to a hose line system of the heat exchanger or are connected, and with the hose line system of the heat exchanger forms at least part of a fluid circuit, as compactly as possible lightweight and autonomously working to a manually portable use z enable u. The cooling unit should be able to be implemented with the simplest possible and inexpensive means and should make it possible to design at least modular partial components as a disposable product or as a so-called disposable. The amount of heat or cold that can be emitted by the device should be provided in the shortest possible time in order to generate the greatest possible cooling or heating output.

The solution to the problem on which the invention is based is specified in claim 1. The features which form the cooling unit according to the solution in an advantageous manner are the subject matter of the subclaims and the further description, in particular with reference to the illustrated embodiment.

The cooling unit according to the features of the preamble of claim 1 is characterized in that an expansion tank is provided with an overflow into which the liquid flows from the storage tank after fluidic access has been generated between the storage tank and the reaction tank. The fluidic access is established by means of a functional means that can locally perforate or open the storage container. The overflow represents a fluid connection to the reaction container through which a portion, preferably the main portion, of the stored liquid enters the reaction vessel for initiating the endothermic reaction with the reactant, preferably in the form of granular urea. The fluid line is fluidly connected to the expansion tank, into which the remaining portion of the stored liquid passes from the storage tank. The remaining portion of the stored liquid is to be understood as the portion of the liquid which does not flow into the reaction container due to the arrangement geometry of the overflow relative to the capacity of the expansion tank. In order to prevent the liquid that has entered the reaction tank through the overflow from flowing back into the expansion tank, a check or reflux valve is preferably arranged along the fluid connection of the overflow. In addition, a fluid pump located outside the reaction container is arranged along the fluid line, which runs at least in regions within the reaction container, and is used to draw fluid from the expansion container into the fluid line running at least in regions within the reaction container.

The fluid line running at least in regions within the reaction vessel further runs fluid-tight to the outside through the reaction vessel wall delimiting the reaction vessel and forms a fluid line section which is referred to hereinafter as a discharge line and is designed in the form of a flexible hose line. The fluid line running inside is made of metal, preferably of aluminum, at least in sections, for reasons of heat transfer to the surrounding medium within the reaction container that is optimized as far as possible. Along the discharge line, a fluid pump is preferably designed and arranged in the form of a roller pump, by means of which a fluid flow flow is impressed into the fluid line by means of a peristaltic pressure exerted on the hose line from the outside, so that the liquid that is located in the expansion tank passes through the Fluid line is sucked off.

Optionally, a filter unit, preferably in the form of a bacterial filter, is introduced along the discharge line leading away from the reaction container.

The drainage of the fluid line is furthermore preferably connected via a detachable, fluid-tight coupling to the inlet of a hose line system which is connected to an inside of a Oxygenators integrated heat exchanger is thermally coupled.

The fluidic output of the hose power system thermally coupling to the heat exchanger is preferably connected to the feed line of the fluid line via a detachable fluid-tight coupling, which leads into the expansion tank.

Thus, the expansion tank, the fluid line and also the hose line system of the heat exchanger form a self-contained fluid circuit, along which the liquid circulates, which serves as the heat transfer fluid of the heat exchanger. It is precisely this liquid portion that serves as the heat transfer liquid that comes from the liquid stored in the storage container, which after appropriate local perforation or opening of the storage container is poured into the expansion tank with the aid of the functional means to be explained in more detail below.

Due to a limited holding volume within the collecting container, which is smaller than the capacity of the storage container, the largest part of the liquid flows over the overflow along the fluid connection into the reaction container in which the reactant is stored, preferably in the form of granular urea. Also suitable are alternative reactants which withdraw thermal energy from the environment with a liquid, preferably water, with the formation of an endothermic chemical reaction.

The amount of liquid stored in the storage container is dimensioned such that the liquid portion flowing via the overflow and the fluid connection into the reaction container is at least 70%, whereas the remaining portion of the liquid is retained within the expansion tank, which, as explained above, acts as a heat transfer fluid for the Heat exchanger fluidly connected to the cooling unit designed according to the solution.

To support and homogenize the chemical, endothermic reaction between the liquid and the granular reaction medium, an agitator is arranged inside the reaction container, which can be driven via a mechanical interface, for example in the form of a gear transmission, with a drive motor arranged outside the reaction container. In order to ensure that no liquid components can get back from the reaction container into the expansion tank, especially since this would contaminate the liquid inside the expansion tank, a check valve is arranged along the fluid connection.

For the purpose of handling the cooling unit designed according to the solution in a simple and error-free manner, the storage container is preferably designed in the form of a liquid bag. For reasons of mechanical protection, the liquid bag is also located within a first housing, which is arranged vertically above a second housing surrounding at least the expansion tank. A third housing enclosing the reaction container is arranged vertically below the second housing surrounding the expansion tank. Optionally, the second and third housing can be formed in one piece. A spacer is additionally arranged between the first and second housing, which secures a predetermined vertical distance between the storage container contained in the first housing and the functional means which is preferably fixedly attached to or within the expansion tank.

The functional means is designed in the form of a sharp-edged object and is preferably arranged vertically below the storage container.

The spacer vertically spacing the storage container from the expansion tank, which prevents direct contact between the storage container and the sharp-edged functional means, is preferably mounted between the first and second housing such that the spacer can be separated laterally from the stacked structure, for example by manual pulling out . After removing the spacer, the storage container falls vertically downwards due to its weight and gravity and comes into contact with the sharp-edged functional means, as a result of which the storage container is mechanically perforated or opened locally, so that the liquid stored in the storage container pours completely into the expansion tank . Simultaneously with the vertical lowering or falling of the storage container and the associated filling of the expansion and reaction container, the fluid pump and the drive motor for activating the agitator within the reaction container are put into operation.

The first housing surrounding the storage container and the second housing arranged vertically underneath are designed in relation to their vertically directly facing sides in such a way that after removal of the spacer, both housings are mechanically unambiguous, for example in the manner of a circumferential tongue and groove connection Form a firm mechanical joint connection.

The cooling unit according to the solution serves for the rapid and efficient provision of a large one Cooling capacity within a very short period of time, which apart from the start-up of the fluid pump and the drive motor does not require any additional electrical power supply. Due to the limited energy requirement, the required electrical energy can be made available as part of a battery.

A preferred embodiment of the cooling unit according to the invention provides for a modular structure such that the electrical components, such as the fluid pump and drive motor, together with the control unit and electrical energy source required for this purpose, are accommodated in a modular, uniform housing. The first housing comprising the storage container, the spacer, the second housing comprising the expansion tank and the third housing comprising the reaction container are each designed as module units which can be stacked vertically one above the other and can be disposed of in the form of disposable items after use.

The cooling unit can basically be fluidly connected and used with a heat exchanger for any application. Heat exchangers in the form of cooling surfaces or cooling mats are conceivable, as are cooling vessels or cooling drums, to name just a few applications. The cooling unit is suitable as a cooling source for heat exchangers that are integrated in stationary or portable cooling units.

Figure list

• 1 schematisierte Darstellung einer lösungsgemäß ausgebildeten Kühleinheit zur Temperierung eines in einem Oxygenator integrierten Wärmetauschers im Stadium vor der Aktivierung der Kühlfunktion,
• 2 schematisierte Darstellung der Kühleinheit nach Aktivierung der Kühlfunktion.

The invention is described below by way of example without limitation of the general inventive concept using an exemplary embodiment with reference to the drawing. It shows:

• 1 Schematic representation of a cooling unit designed according to the solution for temperature control of a heat exchanger integrated in an oxygenator in the stage before the activation of the cooling function,
• 2nd Schematic representation of the cooling unit after activation of the cooling function.

WAYS OF CARRYING OUT THE INVENTION, INDUSTRIAL APPLICABILITY

1 illustrates a cooling unit designed according to the solution in a schematic representation K to provide a cooled heat transfer fluid for operating a heat exchanger W , which is preferably part of an oxygenator O is.

The cooling unit K essentially has four modules M1 to M4 on, of which at least the modules M1-M3 can be assembled vertically one above the other according to the modular principle. The module M1 has a reservoir 1 for a liquid, preferably in the form of water. The storage container is preferably present 1 from a water-filled plastic bag or plastic canister, which is used for protection and mechanical joining with the module underneath M2 from a first housing 2nd is at least partially surrounded.

Vertically below the first module M1 is the second module M2 arranged that a reservoir 3rd includes in which a functional means 4th in the form of a vertically tapering object, for example needle, mandrel, etc., is firmly arranged. The expansion tank 3rd is from a second housing 5 surround. Inside the expansion tank 3rd an overflow protrudes vertically from below 6 with a fluid connection 7 that go vertically from above into the reaction container 8th of the third module M3 that flows from a third enclosure 9 is surrounded. The fluid connection 7 is designed as a pipe open on both sides and has a check valve 10th on that a liquid entry from the side of the reaction container 8th in the expansion tank 3rd prevented. In the reaction tank 8th is a reactant 11 stored in granular form, which preferably consists of granular urea.

Furthermore, opens out in the bottom area of the expansion tank 3rd a fluid line 12 that are inside the reaction vessel 11 continues, preferably with the formation of conduction coils 13 in order to have the largest possible fluid line surface within the reaction container 8th to realize. The fluid line 12 leads through the third enclosure in a fluid-tight manner 9 to the outside and also serves as a derivative 14 the cooling unit K . The inside of the reaction container 9 running fluid line 12 and in particular the line coils located there 13 are made of a highly conductive material, preferably metal, whereas the fluid line along the discharge line 14 consists of a thermally poorly conductive and elastic material, for example plastic.

Along the derivative 14 is a filter unit 15 , preferably in the form of a bacterial filter. Downstream to the filter unit 15 is along the derivative 14 a fluid pump 16 , preferably in the form of a roller pump. Downstream of the fluid pump 16 is a releasable fluid-tight coupling 17th for a fluid-tight connection with the heat exchanger W associated hose line system 18th .

The hose line system is in the same way 18th with a releasable fluid-tight coupling 17` with the as a lead 19th in the expansion tank 3rd the cooling unit K serving fluid line connected.

The third module M3 also has a stirrer 20th , which has a detachable gear unit 21st with a drive motor 22 is coupled. The drive motor 22 , the fluid pump 16 as well as an electronic control unit 23 in combination with an electrical energy source 24th that are used to operate the drive motor 22 and the fluid pump 15 serve, form the fourth module M4 , which is surrounded by a fourth housing, not shown.

The first and second module M1 , M2 are vertical by a spacer 25th vertically spaced so that the functional means 4th in the form of a vertically tapering object within the first module M1 contained storage container 1 not touched. The spacer 25th is sliding between the first and second module M1 , M2 stored and preferably secured with the help of a locking mechanism, not shown, against uncontrolled slipping out of the side.

To activate the cooling unit K the spacer applies 25th from the side of the vertical module assembly M1 , M2 to be removed, for example by pulling it out to the side, see arrow display P .

2nd illustrates the condition after removing the spacer from the side 25th from the modular stacking system. As a result of the missing spacer 25th the reservoir falls 1 including the first housing 2nd vertically downwards, as a result of which the functional means tapering to the top 4th the reservoir 1 perforated locally. To ensure that the drop and join process of the first module M1 on and into the second module M2 done in a certain way, the first and second enclosures point 2nd , 5 on their vertically facing sides, all-round joining contours F on.

As a result of the mechanically initiated perforation of the storage container 1 flows the entire liquid content of the reservoir 1 in the expansion tank 3rd . About 90% of those in the storage container 1 The amount of liquid stored flows over the overflow 6 and the fluid connection 7 in the reaction vessel 8th and initiated with the reactant 11 an endothermic chemical reaction, creating within the reaction vessel 8th cooling takes place. A remainder 26 the liquid remains inside the expansion tank 3rd and serves as a heat transfer fluid for operating the heat exchanger W . Simultaneously with the removal of the spacer 25th and the gravity-driven perforation of the storage container 1 by means of the electronic control unit 23 both the fluid pump 16 as well as the drive motor 22 activated. The fluid pump working as a suction pump 16 sucks the as a residual 16 inside the expansion tank 3rd liquid 26 through the fluid line 12 due to cooling within the reaction area 8th is cooled. The cooled liquid is drained 14 through the filter unit 15 in the heat exchanger W pumped. The after exiting the heat exchanger W outflowing heat transfer fluid passes through the supply line 19th back into the expansion tank 3rd , from the liquid again via the fluid line 12 for the purpose of cooling them in the area of the reaction vessel 8th is sucked.

The first, second and third modules are advantageous M1 , M2 , M3 designed as a disposable item, whereas the fourth module, which comprises the electrical components M4 can be reused as often as required. The filter unit 15 is preferably an integral part of the third module M3 and therefore also part of a disposable item.

Reference symbol list

1

Storage container

2nd

first housing

3rd

surge tank

4th

Functional means

5

second housing

6

Overflow

7

Fluid connection

8th

Reaction vessel

9

third housing

10th

check valve

11

Reactant

12

Fluid line

13

Conduction coil

14

Derivative

15

Filter unit

16

Fluid pump

17, 17`

releasable fluid-tight coupling

18th

Hose line system

19th

Supply

20th

Stirring tool

21st

Gear unit

22

Drive motor

23

electrical control unit

24th

electrical energy source, battery

25th

Spacers

26

Residual portion of the liquid

W

Heat exchanger

O

Oxygenator

M1, M2, M3, M4

Modules

P

Arrow direction

K

Cooling unit

F

Joining contour

Claims (13)

Cooling unit for a heat exchanger, preferably a heat exchanger (W) integrated in an oxygenator (O) for tempering blood carried in an extracorporeal blood circuit, with - a storage container (1) holding a liquid, - a reaction container (8) comprising a reaction medium (11) ), which is able to initiate an endothermic reaction in connection with the liquid, - a functional means (4) generating fluidic access between the storage container (1) and the reaction container (8) and - a fluid line running at least in regions within the reaction container (8) (12), which has an inlet and outlet (14, 19), each of which can be connected or connected in a fluid-tight manner to a hose line system (18) of the heat exchanger (W), and at least to the hose line system (18) of the heat exchanger (W) forms part of a fluid circuit, characterized in that an expansion tank (3) with an overflow (6) It is provided, into which the liquid flows from the storage container (1) after fluidic access has been generated between the storage container (1) and the reaction container (8), that the overflow (6) represents a fluid connection (7) to the reaction container (8) through which a Portion of the stored liquid in the reaction container (8) for initiating the endothermic reaction with the reactant (11) reaches that the fluid line (12) is fluidly connected to the expansion tank (3) into which a remaining portion (26) of the stored liquid flows reaches the storage container (1) and that a fluid pump (16) is arranged along the fluid line (12) by means of the liquid from the expansion container (3) into the fluid line (12) running at least in regions within the reaction container (8). Cooling unit after Claim 1 , characterized in that a non-return valve (10) is arranged along the fluid connection (7) of the overflow (6), which prevents the liquid from flowing back from the reaction container (8) into the compensating container (3). Cooling unit after Claim 1 or 2nd , characterized in that the fluid pump (16) is designed in the form of a suction unit which runs along the fluid line (12) outside the equalizing and reaction container (3, 8) downstream to the region of the fluid line (12) running inside the reaction container (8) ) is arranged. Cooling unit after Claim 1 or 2nd , characterized in that the fluid pump (16) is designed as a roller pump. Cooling unit according to one of the Claims 1 to 4th , characterized in that the fluid line (12) downstream of the area running inside the reaction vessel (8) provides the discharge line (14), and that upstream of the discharge line (14) a filter unit (15) is arranged along the fluid line (12). Cooling unit after Claim 5 , characterized in that the filter unit (15) is a bacterial filter. Cooling unit according to one of the Claims 1 to 6 , characterized in that the feed line (19) of the fluid line (12) opens into the expansion tank (3) and that the fluid circuit consists of the expansion tank (3), the fluid line (12) and the hose line system of the heat exchanger (W) which the remaining portion (26) of the liquid circulates as the heat transfer liquid of the heat exchanger (W). Cooling unit according to one of the Claims 1 to 7 , characterized in that the storage container (1) is arranged vertically above the compensating container (3), that the functional means (4) is designed in the form of a sharp-edged object which is arranged vertically below the storage container (1), that between the storage container ( 1) and the expansion tank (3) a spacer (25) is arranged, which holds the storage tank (1) vertically above the functional means (4), and that the storage tank (1) after removing the spacer (25) gravity gears in contact occurs with the functional means (4), which consequently mechanically penetrates the storage container (1) locally, so that the liquid stored in the storage container (1) pours completely into the expansion tank (3). Cooling unit according to one of the Claims 1 to 8th , characterized in that the functional means (4) on the expansion tank (3) is fixed. Cooling unit according to one of the Claims 1 to 9 , characterized in that an agitator (20) is arranged inside the reaction container (8) and can be driven via a mechanical interface with a drive motor (22) arranged outside the reaction container (8). Cooling unit according to one of the Claims 1 to 10th , characterized in that at least the storage container (1), the functional means (4) and the reaction container (8) are designed as disposable items. Cooling unit according to the Claims 5 , 10th and 11 , characterized in that the filter unit (15) and the agitator (20) are parts of the disposable item and the drive motor (22) and the fluid pump (16) are connected to an electrical energy source (24) and an electrical control (23) and as modular Unit are designed for mechanical adaptation to the disposable item. Cooling unit according to one of the Claims 1 to 12 , characterized in that the heat exchanger (W) is integrated in a stationary or portable cooling unit.

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